Method and apparatus for activating compound semiconductor

Abstract

A compound semiconductor is placed in a reaction vessel ( 12 ) of which the inner gas is subjected to replacement with a low-vapor-pressure gas ( 2 ) whose equilibrium vapor pressure at the melting point of the compound semiconductor is 1 atm or lower. The low-vapor-pressure gas is urged to flow along the surface of the compound semiconductor while keeping the internal pressure of the reaction vessel at a value not lower than that equilibrium vapor pressure. The surface of the compound semiconductor is irradiated with a pulsed-laser light ( 3 ) whose photon energy is higher than the band gap of the compound semiconductor. Thus, only that part of the compound semiconductor which is located at the pulsed-laser light irradiation position is instantly heated and melted while keeping the atmospheric temperature of the low-vapor-pressure gas at a room temperature or a temperature equal to or lower than the decomposition temperature.

1. A method for activating a compound semiconductor, comprising the steps of:
 placing the compound semiconductor in a reaction vessel; 
 replacing an inner gas in the reaction vessel with a low-vapor-pressure gas whose equilibrium vapor pressure at a melting point of the compound semiconductor is one atmospheric pressure or lower; 
 causing low-vapor-pressure gas to flow along a surface of the compound semiconductor while keeping an internal pressure of the reaction vessel at a value equal to or higher than the equilibrium vapor pressure; and 
 irradiating a pulsed-laser light whose photon energy is higher than a band gap of the compound semiconductor to the surface of the compound semiconductor, 
 thereby permitting only a part of the compound semiconductor located at an irradiation position of the pulsed-laser light to be melted while allowing an atmospheric temperature of the low-vapor-pressure gas to be kept at a room temperature or a temperature not higher than a decomposition temperature. 
 
     
     
       2. The method according to  claim 1 , wherein:
 the compound semiconductor comprises gallium nitride, and 
 the low-vapor-pressure gas comprises a gas selected from ammonia gas, hydrazine gas, and mixed gas thereof. 
 
     
     
       3. The method according to  claim 1 , wherein the pulsed-laser light is homogenized and shaped by a homogenizer to become a shaped line beam. 
     
     
       4. The method according to  claim 1 , wherein the pulsed-laser light is irradiated onto the surface of the compound semiconductor while transferring the compound semiconductor along a laser irradiation surface. 
     
     
       5. The method according to  claim 1 , wherein rare earths and transition metal such as erbium (Er), terbium (Tb), or europium (Eu) is ion implanted into the compound semiconductor. 
     
     
       6. The method according to  claim 1 , wherein alkali metal such as sodium, potassium, or lithium is ion implanted into the compound semiconductor. 
     
     
       7. The method according to  claim 1 , wherein a p-type impurity, an n-type impurity, or p-type and n-type impurities is ion implanted into the compound semiconductor.